Wednesday, October 23, 2013

It's been a roller-coaster month for many scientists. In the US, there was a government shut-down. And in the wider community, there have been a number of news article on some interesting, but inconclusive experimental finding. The goal of this post is to highlight the findings and give people links to the articles by Scientific American and New Scientist.

So, a list of some recent experimental findings:

(1) Dark Matter particles likely have rest mass between 8 keV and 14 keV
Horiuchi et al. recently published a paper that compares experimental measurements with dark matter theory suggests that the rest mass of dark matter particles is somewhere between 8 keV and 14 keV. Only in this range of values of the rest mass can the number of experimentally measured subhalo counts be predicted. (See Figure 2 and Table II from their paper below.) This appears to be strong experimental evidence against dark matter with rest mass values of MeV or GeV. I look forward to see more data collection and analysis along these lines.

The NIF is an exciting research facility because it allows us to understand nature better and because it helps us understand the D-T fusion process used for military applications. However, I'm afraid that what we've learned this week is that the science media (once again) goes after whatever can get hype.

So, let's be clear with what happened at NIF last month.

192 lasers generated photons that had 1.8 MJ of energy. (It should be pointed out that the NIF site consumed well more than 1.8 MJ of electricity to create the 1.8 MJ of photons. If this had been a semi-continuous event, the lasers would likely need at least 5 MJ to create the 1.8 MJ in photons.)

Of the 1.8 MJ in the photons, less than 14 kJ of energy reached the inside of the target as high energy X-rays. And 14 kJ of neutrons were generated from the reaction. Assuming that the neutrons are used to run a Rankine cycle power plant (same as for nuclear fission), then we are talking about roughly 5 kJ of electricity could be generated from the neutrons.

This means that the site spent ~5MJ of electricity to be able to perhaps obtain 5 kJ of electricity.

This means that NIF is three orders of magnitude away from "breakeven," and four orders of magnitude after from being "thermodynamically viable." This is far from a "milestone", and it is far away from what has already been achieved by the magnetically-confined fusion plasmas at JET.

I think that it's silly that NIF is trying to sell itself as an energy source of the future.

With that having been said, I want to point out that the idea of nuclear fusion is not a complete pipe dream. There is a possibly viable route to electricity production via magnetically-confined fusion plasmas, such as the still-being-built ITER experiment in Cadarache, France.

While this experiment is really expensive and there's still a chance that there's another plasma instability that will keep the system from reaching the real "breakeven" milestone (i.e. of generating more potential electricity from the neutrons than the electricity consumed to heat the plasma), I am proud that this facility is getting funding from world governments, including the US. The research at ITER is ground-breaking, and magnetically-confined fusion plasma is a potential energy source in the future if we can figure out how to control a few more of the instabilities have have appeared over the last ~60 years of research in this field.

I'd like to end this post by detailing some more information on some of the main engineering breakthroughs required before magnetically-confined fusion plasma can become "engineering" viable.

List of engineering breakthroughs required for magnetically-confined fusion plasma
(Also see slide 4 of the following presentation. The required engineering 'feats' or breakthroughs are well known. The required feats are all likely achievable...just really damn hard and require lots of upfront capital to do the research.)
(1) Controlling any instabilities that occur through alpha-heating (i.e. there are likely to be instabilities due to the fact that the alpha particles emerge with energies on the order 4 MeV, but the core temperature of the plasma may only be 100's of keV.) The ability to control potential instabilities in nuclear fusion powered plasmas will be tested at ITER.
(2) Not-steady-state: Tokamak plasmas have a torodial electric field that must be applied by a time-varying magnetic field. This means that the process is inherently not-steady-state because you eventually need to change the direction of the electric field as you reach the maximum magnetic field that can be generated. This means that the plasma needs to be turned off (likely on a weekly/monthly basis), and then the current needs to be restarted in the opposite direction. An engineering 'feat' is required here to design a system that doesn't break during these scheduled start-ups / shut-downs (or a breakthrough is required in steady-state plasmas) and that isn't cost prohibitive. So far, the steady-state stellarators designs have been cost-prohibitive.
(3) The wall materials that can withstand high flux of ions, electrons, photons, and neutrons still need to be tested and proven to work. Also, the process for generating Tritium from Lithium needs to be demonstrated on a continuous basis. (Note: there are plans to do this testing. I'm just point out that this has still been yet to demonstrated.)
(4) There are also a number of challenges associated with making cheap, super-conducting, high field magnets, with fueling the plasma, with removing heat, and with designing wall materials to withstand instabilities that release large amounts of energy to the wall while not releasing material from the wall that can end up cooling off the core of the plasma.

My overall conclusion (i.e. educated guess) is that magnetically-confined fusion plasma may be engineering-feasible sometime in the next 50 years, but it may not be economically competitive in the next 100 yrs. There's just too much uncertainty to known if magnetically-confined fusion will ever be economically viable against other sources of energy.

What can be stated with 99% certainty is that inertially-confined, laser-driven fusion is nowhere close to being engineering-viable or economically-viable. As a tax-payer in the US, I'd like to be able to vote for where my taxes goes. I would be willing to vote for magnetically-confined fusion plasma research, but I would not vote for my tax dollars to go to inertially-confined fusion research.

Sunday, October 6, 2013

What do coral reefs off of the coast of Australia, computer
chip factories in Thailand, ski&snowboarding resort on the US east coast, and
islands in the South Pacific all have in common? The answer is that all of these
places are already feeling the negative impact of human-induced increases in
the concentration of CO2 into the atmosphere.

The goal of this post is explain the science behind the
effects of higher CO2 levels in the atmosphere, such as global
warming, ocean acidification, and sea level rises. My hope is to explain in a
somewhat less-technical manner the effects of higher CO2
concentrations in the atmosphere compared with the recent
publication by the IPCC. There's nothing wrong with how the IPCC presents
this information; it's just that I think that it's help for the information to
be presented by the eyes of somebody who has no connection to those people who
wrote the report or the papers cited in the report.

Unfortunately, the topic of CO2 emissions has
become so politicized that the actual facts are easily swept under the rug of
political ideology. Part of the problem is that environmental groups rarely
discuss the actual science (and are quick to bash people who aren't alarmists),
and the other part of the problem is clearly that there are people who refuse
to accept that humans can affect the global climate, the ocean pH, or the sea
level. I consider myself a fairly
moderate person and my goal here is to tell it as it is, regardless of how
difficult it may or may not be to solve the problem of preventing major changes
to Earth's climate, to Earth's average sea/ocean level, and Earth's average pH
level in the seas/oceans.

So, before I get into the science, I'd like to state simply
what the actual problem is that we face:

The problem: Our
global society is on pace to cause the temperature in Arctic and Antarctic to
raise to the point at which we will likely see at least a 3 meter increase in
sea levels. In addition, the higher concentration of CO2 in the atmosphere will
cause lower pH levels in the ocean, which is harmful to major shell forming species,
such as coral reefs. These are the straight-forward and indisbutable effects of
higher concenrtations of CO2 in the atmosphere. There are also a number of
other effects, of varying levels of certainty.

The Solution: The only realistic way to prevent major
climate change, sea level change and pH change is to globally limit the
emission of CO2 into the atmosphere. We can't
"geo-engineer" our way out of this problem by throwing particulates
into the atmosphere to scatter light from hitting the surface because this
"solution" doesn't solve the fact that the pH of the ocean will
continue to decrease if we were to continue to emit large amounts of CO2
into the atmosphere.

Three Worlds, Three Mysteries

The Goal of this Blog

My goal is to communicate how life can expand and grow, both on this planet and on others. To grow, we need to obtain a large rate of return on investment from our power plants, so a main focus of this blog is on the economics of electricity generation and vehicle transportation.To summarize, the goal of life is to expand. Life requires mechanical or electro-chemical work to survive, and to grow, it requires a large, positive rate of return on work invested.

In other words, the purpose of a power plant is to make more power plants, and as quickly as possible.

After a series of posts on the topic of energy policy and economics, I thought that it'd be a good time to take a break and delve back i...

Good quotes

"The [engineer] should be equipped with knowledge of many branches of study and varied kinds of learning, for it is by his judgement that all work done by the other arts is put to test. This knowledge is the child of practice and theory."

Marcus Vitruvius Pollio, De Architectura, (~15 BC)

"The fact that the Standard Model of Physics has just enough complexity to be able to accommodate CP violation does not shed any light on the true nature of this phenomenon, and we feel the conclusion of J. Cronin's 1980 Nobel speech still stands: 'We must continue to seek the origin of the CP symmetry violation by all means at our disposal. [...] We are hopeful, then, that at some eposh, perhaps distant, this cryptic message from nature will be deciphered.' (Cronin, 1981) --Marco Sozzi, 2008, from the Coda of Discrete Symmetries and CP Violation

"Knowledge is power."

"Lastly, I would address one general admonition to all; that they consider what are the true ends of knowledge, and that they seek it not either for pleasure of the mind, or for contention, or for superiority to others, or for profit, or fame, or power, or any of these inferior things; but for the benefit and use of Life; and that they perfect and govern it in charity."— Francis Bacon

"Dare to be an optimist."

—Matt Ridley

"Stretch the range of human powers...Give us new metaphors with which to puzzle out our mysteries...Give us pride and higher aspirations...Turn our trash into treasure...Give us goals and meaning...Give us new tools with which we can connect...Validate us in our moments of confusion...Give us new rituals to make sense of our day...Give us new levels of reality...Give us your soul and bare your emotions...Give us new tools of understanding...Turn luxuries into everyday commodities...Warn us of our failings, of our conplacency, or our alternatives and of our dangers...Help us serve a purpose higher than ourselves."

—Howard Bloom, The Genius of the Beast

“Progress is possible only when people believe in the possibilities of growth and change. Races or tribes die out not just when they are conquered and suppressed, but when they accept their defeated condition, become despairing, and lose their excitement about the future.”—Norman Cousins

"If I had to choose a religion, the sun as the universal giver of life would be my god."— Napoleon Bonaparte

"Knowledge is of no value unless you put it into practice."— Anton Chekhov

"There is only one good, knowledge, and one evil, ignorance."

"Let no one ignorant of Mathematics enter [the Academy]."

— Plato/Socrates

"Perhaps the only goal on earth to which mankind is striving lies in this incessant process of attaining, in other words, in life itself..."

— Narrator of Dostoevsky's Notes from the Underground

"The physical holds no power over destiny."

—Norman Paperman

"Nature is not solely physical, even though everything in it must depend on the physical. Nature includes not only physical entities but complex material organizations, mathematical lawfulness, possibilities, life, need, behavior, intelligence, purpose, societies, minds, meanings, signs, and knowledge."

— Lawrence Cahoone, "The Orders of Nature"

"All men by nature desire knowledge."— Aristotle

"Worrying is praying for something that you don't want. So stop worrying!"

—Bhagavan Das

"Keep your head above the water and bet on the growth of your country."— Henry Flagler of Standard Oil

"Society will develop a new kind of servitude which covers the surface of society with a network of complicated rules, through which the most original minds & and the most energetic of characters cannot penetrate. It does not tyrannize, but it compresses, enervates, extinguishes & stupefies a people until each nation is reduced to nothing better than a flock of timid & industrious animals, of which the government is the shepherd."

"Socrates: 'Now, that which imparts truth to the known and the power of knowing to the knower is what I would have you term the idea of good, and this you will deem to be the cause of science, and of truth in so far as the latter becomes the subject of knowledge; beautiful too, as are both truth and knowledge, you will be right in esteeming this other nature as more beautiful than either; and, as in the previous instance, light and sight may be truly said to be like the sun, and yet not the sun, so in this other sphere, science and truth may be deemed to be like the good, but not the good; the good has a place of honor yet higher.'Glaucon: 'What a wonder of beauty that must be, which is the author of science and truth, and yet surpasses them in beauty; for you surely cannot mean to say that pleasure is the good?'

Socrates: 'God forbid, but I may ask you to consider the image in another point of view.'

Glaucon: 'In what point of view?'

Socrates: 'You would say, wouldn't you not, that the sun is not only the author of visibility in all visible things, but of generation and nourishment and growth, though he himself is not generation?'

Glaucon: 'Certainly.'

Socrates: 'In like manner, the good may be said to be not only the author of knowledge to all things known, but of their being and essence, and yet the good is not essence, but far exceeds essence in dignity and power.' "